Researchers in the Procedures for Adopting Educational Innovations Program at the University of Texas have developed an "Intervention Taxonomy" to help classify and define interventions and components of interventions. It is hoped that this taxonomy will enable change facilitators and researchers to make conceptual and operational distinctions among actions and events that influence innovations. Data were obtained from descriptive protocols developed by ethnographers observing interventions over a two- to three-year period in school systems undergoing change. The data have been the subject of quantitative and qualitative analyses. As well as providing definitions, the taxonomy identifies several levels of intervention from policy level down to incident level. A distinction is made between sponsored and unsponsored interventions and their components. Implications drawn from the study are that (1) a change effort succeeds or fails at the incident (lowest) level, (2) the "game plan" for a change effort should be specified in detail and in advance, (3) how long unplanned influences on the change effort are allowed to continue is directly related to the skill of the change facilitator, (4) developing stereotypic names to classify interventions may be useful, and (5) coding systems for other levels of interventions may be useful. (Author/JM)